A264844 Centered 19-gonal (or nonadecagonal) primes.

191, 1483, 2281, 5701, 11971, 14821, 15581, 21433, 26183, 39521, 43283, 54151, 60041, 61561, 72733, 81283, 120233, 135661, 137941, 166783, 187531, 220933, 229711, 244721, 282683, 292601, 306091, 323381, 378101, 409033, 457711, 461891, 478801, 513533, 526871

Offset: 1

Author

Ilya Gutkovskiy, Nov 26 2015

Keywords

• nonn

Comments

Primes of the form (19*k^2 - 19*k + 2)/2.

Links

• Robert Israel, Table of n, a(n) for n = 1..10000
• OEIS Wiki, Figurate numbers
• Eric Weisstein's World of Mathematics, Centered Polygonal Number
• Eric Weisstein's World of Mathematics, Prime Number

Crossrefs

Cf. A069132, A000040.

Programs

Maple

select(isprime, [seq((19*k^2-19*k+2)/2,k=0..10^4)]); # Robert Israel, Jul 02 2024

Mathematica

Select[(19 #^2 - 19 # + 2)/2 &@ Range@ 250, PrimeQ] (* Michael De Vlieger, Nov 27 2015 *)

PARI

for(n=1, 1e3, if(isprime(k=(19*n^2-19*n+2)/2), print1(k, ", "))) \\ Altug Alkan, Nov 26 2015